abstract |
A method is provided for depositing a uniform thin film on a substrate using laser ablation of a target material in a deposition chamber. The laser beam may be pulsed and focused to strike the target along a line to produce a broad plume of ablated material expanding in a propagation direction outward from the target. The plane of the substrate deposition surface is oriented generally parallel to the propagation direction of the plume of ablated material. The deposition chamber includes a low background pressure of inert or reactive gas to facilitate lateral diffusion of ablated atoms, ions, and molecules to be deposited on the substrate surface. Particles ejected from the target material, which have trajectories generally parallel to the propagation direction of the plume, are too heavy to have significant lateral diffusion and have little chance of lodging on the deposition surface. The substrate may be rotated about an axis perpendicular to the deposition surface (and generally perpendicular to the propagation direction of the plume) to provide uniform deposition over the entire surface. The method may also be used to deposit thin films on both sides of a substrate simultaneously, and on multiple substrates by stacking them in the plume in space-apart orientation. |